In electrical systems, flexible printed circuits are often employed as electrical jumpers or cables for interconnecting rows of terminal pins or posts of printed circuit boards comprising the subsystems. A connector, mounted to one or both ends of the jumper, is formed with a set of electrical receptacles or sockets which are designed to receive the terminal posts on the printed circuit board. One type of connector, shown in U.S. Pat. No. 4,225,205, for example, is mounted to the end of the flexible cable and solder connections are made between the circuit terminations of the flexible circuit and various sockets or clips of the connector. Since there may be a large number of such terminations, each one of which must be soldered separately from the others, the attachment of the connector to the flexible circuit can be a time-consuming and tedious process. Furthermore, there is great potential for misconnection of the printed circuit paths to the connector due to solder bridging of adjacent circuit paths or due to a dead solder connection. Also, if connections are to be made in the field, this requires that the technician carry a soldering gun which can be inconvenient. Moreover, the connection is a permanent one.
In another type of connector arrangement, the connector is releasably engaged on the end of the flexible circuit. The connector has a set of spring contacts which resiliently engage the printed circuit paths of the flexible circuit, with the opposite ends of those contacts being soldered to terminal pads or posts of the PC board being connected to. While this type of connection is releasable, it still requires that individual solder connections be made in each circuit path between the two circuits.
U.S. Pat. Nos. 4,531,793 and 4,583,800 are illustrative of connectors which eliminate completely the need to solder when connecting a flexible printed circuit to a printed circuit board. In these systems, the connector is basically a spring-like clamp which clamps the printed circuit paths of the flexible circuit to congruent circuit paths of the PC board. However, this type of connection is possible only when the circuit path terminations of both circuits being connected are planar or flat, i.e. are pads. Such connections could not be used to establish contacts with a PC board whose terminations are upstanding pins or posts.
There is one type of solderless connector of which we are aware which enables one to releasably connect a flexible printed circuit to termimal posts of a PC board. In this arrangement, disclosed in U.S. Pat. No. 4,172,626, a clip having a row of spring members is mounted to the PC board by way of tabs which project through openings in the PC board and are bent over at the underside of the board. The spring members in the clip are arranged so that they are disposed directly opposite the posts of the PC board. The terminal pads of the flexible circuit to be connected to the PC board are arranged so that when the end of the flexible circuit is inserted into a gap between the spring members and the wire wrap posts, the flexible circuit pads are sandwiched and clamped between the spring members of the clip and the posts of the PC board thereby establishing electrical contacts between the terminal pads of the flexible circuit and the posts of the PC board. A special halter impaled on the flexible circuit interfits with the clip to hold the two circuits together. This connection arrangement thus requires that special holes be provided in the PC board being connected to in order to mount the clip. Another set of holes is required in the flexible circuit in order to mount the halter. Also that connector requires an assembly of parts at the connection site in order to couple the two circuits. Such assembly may be difficult to accomplish when the connection site is congested and out of the technician's view. Also, this last-mentioned prior connector must be formed of special metal by a fairly complex rolling operation in order to provide spring members which function as springs as well as current paths between the two circuits being connected.